--- /dev/null
+/*
+ * Copyright (c) 2012 Big Switch Networks, Inc.
+ *
+ * Licensed under the Eclipse Public License, Version 1.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License.
+ *
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+ *
+ * Originally created by David Erickson, Stanford University
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an "AS
+ * IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+ * express or implied. See the License for the specific language
+ * governing permissions and limitations under the License.
+ */
+
+package org.opendaylight.controller.hosttracker.internal;
+
+import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Iterator;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.opendaylight.controller.hosttracker.Entity;
+import org.opendaylight.controller.hosttracker.IDeviceService;
+
+/**
+ * An index that maps key fields of an entity uniquely to a device key
+ */
+public class DeviceUniqueIndex extends DeviceIndex {
+ /**
+ * The index
+ */
+ private final ConcurrentHashMap<IndexedEntity, Long> index;
+
+ /**
+ * Construct a new device index using the provided key fields
+ *
+ * @param keyFields
+ * the key fields to use
+ */
+ public DeviceUniqueIndex(EnumSet<IDeviceService.DeviceField> keyFields) {
+ super(keyFields);
+ index = new ConcurrentHashMap<IndexedEntity, Long>();
+ }
+
+ // ***********
+ // DeviceIndex
+ // ***********
+
+ @Override
+ public Iterator<Long> queryByEntity(Entity entity) {
+ final Long deviceKey = findByEntity(entity);
+ if (deviceKey != null)
+ return Collections.<Long> singleton(deviceKey).iterator();
+
+ return Collections.<Long> emptySet().iterator();
+ }
+
+ @Override
+ public Iterator<Long> getAll() {
+ return index.values().iterator();
+ }
+
+ @Override
+ public boolean updateIndex(Device device, Long deviceKey) {
+ for (Entity e : device.entities) {
+ IndexedEntity ie = new IndexedEntity(keyFields, e);
+ if (!ie.hasNonNullKeys())
+ continue;
+
+ Long ret = index.putIfAbsent(ie, deviceKey);
+ if (ret != null && !ret.equals(deviceKey)) {
+ // If the return value is non-null, then fail the insert
+ // (this implies that a device using this entity has
+ // already been created in another thread).
+ return false;
+ }
+ }
+ return true;
+ }
+
+ @Override
+ public void updateIndex(Entity entity, Long deviceKey) {
+ IndexedEntity ie = new IndexedEntity(keyFields, entity);
+ if (!ie.hasNonNullKeys())
+ return;
+ index.put(ie, deviceKey);
+ }
+
+ @Override
+ public void removeEntity(Entity entity) {
+ IndexedEntity ie = new IndexedEntity(keyFields, entity);
+ index.remove(ie);
+ }
+
+ @Override
+ public void removeEntity(Entity entity, Long deviceKey) {
+ IndexedEntity ie = new IndexedEntity(keyFields, entity);
+ index.remove(ie, deviceKey);
+ }
+
+ // **************
+ // Public Methods
+ // **************
+
+ /**
+ * Look up a {@link Device} based on the provided {@link Entity}.
+ *
+ * @param entity
+ * the entity to search for
+ * @return The key for the {@link Device} object if found
+ */
+ public Long findByEntity(Entity entity) {
+ IndexedEntity ie = new IndexedEntity(keyFields, entity);
+ Long deviceKey = index.get(ie);
+ if (deviceKey == null)
+ return null;
+ return deviceKey;
+ }
+
+}